home › event - the identification of recombination centers in organic solar cells

EVENT:

The Identification of Recombination Centers in Organic Solar Cells
Conferences & Talks

TechConnect WORLD 2012: Cleantech Conference & Showcase 2012

21 June 2012
11:00-11:20am
Santa Clara Convention Center, Santa Clara, California

 

description

To achieve high efficiency bulk heterojunction organic solar cells, it is necessary to identify and minimize the recombination centers that limit the performance. There is growing evidence that the dominant recombination is through trap states near the heterojunction interfaces, at least in some cell materials, but there is little information about the nature of the traps. We describe sensitive measurements of transient photoconductivity and of the photocurrent spectral response that provide the density of states distribution and the trap characteristics. These measurements show that prolonged light illumination induces deep traps near the heterojunction interface, high temperature annealing introduces a broadening of the band tail states and fullerene doping can introduce shallow traps. Each type of state acts as recombination centers with different characteristic properties